PLYMOUTH – Four months after federal nuclear regulators downgraded Pilgrim nuclear power plant because of frequent shutdowns, the Nuclear Regulatory Commission has named a new senior resident inspector for the 685-megawatt plant.

The selection of Erin Carfang as the new inspector has nothing to do with recent problems at Pilgrim, NRC officials said.

But the federal agency does rotate resident inspectors and prohibits any one inspector from working at one nuclear plant for more than seven years.

“We do not want these inspectors to develop any ties that could in any way cloud their objectivity when it comes to assessing plant performance,” NRC spokesman Neil Sheehan said.

Carfang is replacing Max Schneider, who was the senior inspector at Pilgrim for seven years. A former U.S. Navy officer, Carfang is coming to Pilgrim from the Beaver Valley nuclear plant in Pennsylvania, where she was a resident inspector.

The inspector’s arrival coincides with increased NRC scrutiny of Pilgrim. Last February, the NRC deemed Plymouth’s nuclear plant degraded, placing it on a list with seven others in the U.S. in the same category.

The downgrading of Pilgrim came after last October’s “scram,” or unplanned shutdown, when the plant lost power from a 345-kilovolt NStar line that provides the plant with electricity.

That shutdown – the second such incident in 2013 – lasted a week. Pilgrim was offline more than 80 days in 2013, with 46 of those days from scheduled refueling and maintenance.

Pilgrim, which is owned by the Lousiana-based Entergy Corp., is also planning to transfer about 6 percent of its total spent nuclear fuel from wet pools into three dry casks made of concrete and steel.

Pilgrim is fast approaching the limit of what its pools can hold. The plant has more than 500 metric tons of spent fuel – or 3,222 fuel assemblies – in pools and is licensed for only 3,859 fuel assemblies.

The NRC estimates that more than 70,000 metric tons of spent nuclear fuel has accumulated in the U.S., with about three-fourths of it still stored and cooled in 40-foot-deep pools at nuclear power plants.

The two resident inspectors at Pilgrim can be reached at 508-747-0565.

Chris Burrell may be reached at cburrell@ledger.com or follow him on Twitter @Burrell_Ledger.